Circuit breaker



July 18, 1939. R ROWE 2,166,555

CIRCUIT BREAKER Filed Jan. 3, 1938 2 Sheets-Sheet 1 INVENTOR RNEY R. N. ROWE CIRCUIT BREAKER July 18, 1939.

Filed Jan. 5, 1958 2 Sheets-Sheet 2 I I INVENTOR nlI RNEY Patented July 18, 1939 PATENT OFFICE CIRCUIT BREAKER Raymond N. Rowe, Plainville, Comp, assignor to The Trumbull Electric Manufacturing Company, Plainville, Conn.,

Connecticut Application January 3,

12 Claims.

My invention relates particularly to comparatively small compact devices adapted to be employed either separately or in gangs for controlling household lighting and comparatively small 5 household and industrial power circuits.

One object is to'provide a snap action or quick make and break type of switch which can normally be operated manually and which will open the circuit automatically in case of an overload.

Another object is to provide a switch of this type which will satisfactorily open the circuit in case of either an ordinary overload or in case of a short circuit and consequent sudden surge.

Another object is to provide a switch of this 15 character which can be readily re-set by hand after automatic tripping.

In certain respects this invention constitutes an improvement over the construction claimed in my application Serial Number 120,159, filed 30 January 12, 1937, now Patent 2,126,412 issued August 9, 1938.

A special object of the present invention is to provide mechanism which under certain circumstances is more eiiective in its action.

55 Another object is to provide a switch which can be tripped automatically either by a thermally actuated device or by an electromagnetic device.

Another object is to provide a snap switch to which will positively open the circuit upon an overload even though the usual throwing spring is broken or so weakened that it is not effective.

Another object is to provide a switch in which the overload circuit opening device moves in 5 the same direction as the movable switch contact when the circuit is opened automatically.

Another object is to provide means for arranging a number of such switches or circuit breakers in a gang where they may all be operated by a single handle action and so that all of the switches in such a gang may be simultaneously tripped by the automatic tripping of any one of the individual switches.

Fig. 1 is a side view of a construction embody- 3 ing certain improvements of my invention, the

current carrying parts being shown in dotted lines.

Fig. 2 is a plan View of the same.

Fig. 3 is a cross sectional view showing three units connected together.

Fig. 3a is a detail view of one of the parts shown in Fig. 3.

I Fig. 4 is an enlarged side view and partial section showing the principal parts of the mechai nism inthe closed circuit or "on position.

a corporation of 1938, Serial No. 183,074

Fig. 5 is an edge view of the mechanism re'- moved from the casing.

Fig. 6 is a. side view of the mechanism with the parts shown in the open circuit position after automatic operation by the thermostatic trip- 5 ping mechanism.

Fig. 7 is a plan view of parts of the mechanism showing the load responsive means for tripping the switch.

Fig. 8 is an exploded view of the movable parts 10 of the mechanism.

In its preferred form the casing for enclosing the parts has a body III with a top part I l suitably secured thereto.

The circuit terminals l2 and I3 are located in opposite corners of the body of the casing in a position convenient for wiring. The switch contacts consist of the stationary member l4 and pivoted member I5. The latter is connected by a flexible conductor IE to the movable end of a bimetallic thermostatic strip 11. The other end of this strip is connected to the base plate l8 mounted in the bottom of the body of the casing.

The overload magnet coil 19 is supported by and has its core connected to the opposite end of .this base plate l8. One end of the coil is electrically connected to the base plate and the other end is connected to a hook 20' on the inner end of the connector 20. The metal frame 2| is suitably mounted upon but insulated from the base plate l8 and has'slots in its opposite sides which provide pivotal supports 22 for the switch member IS. A part'23 of the arm of this switch member 15 swings between the adjacent uprights of the frame 2|.

The actuator lever. which constitutes a part of the handle or operating means is pivoted at 25. The finger piece 21 of this handle member pro- Jects from the front of the casing and has an arcuate portion 28 which slides over a correspondingly shaped front portion 29 set in from the outer face of the top piece I I. A pin or screw 30 is secured to the finger piece 21 and'extends through a slot in the face of the piece 20 into engagement with the outer end of the actuator 24 so that when the finger piece is moved back and forth it will operate the actuator 24.

A shield 31 carried by the pin 30 inside the casing serves to keep the slot closed at all times.

The frame 2| is provided with a lug 32 which serves as a stop for the actuator lever 24 when it is moved to the on or closed circuit position of Fig. 4. The actuator lever has an extension arm 33 which engages a stop lug 34 on the frame when the actuator is moved to the open against one edge of the frame circuit or off position of Fig. 6. The helical tension spring 35 has one end connected to a bridge 36 in the outer end of the actuator 24 and the other end correspondingly connected to the switch member 15 at the point 31. The action of the parts thus far described is that of the usual snap action throw-over to snap the switch member off and on.

When the switch is operated to open the circuit in the normal manual way the finger piece 21 is moved to the right from the position of Fig. 4. The lever 24 is thus tilted aboutits pivot 25 (which is normally stationary). The tension on the spring 35 is thus increased until the line connecting points 36 and 31 passes to the right of the pivot 22 of the switch member whereupon the tension of the spring 35 pulls the switch member to the open circuit position. The circuit may be closed by the simple movement of the lever21 to the left in the usual manner.

I The switch actuator 24, however, instead of being hinged on a fixed axis is mounted at 25 on a pivot which is carried by a kick-off member 40 which in turn is pivoted at 4| to the frame 2|. A toggle arm 42 is hinged at one end at 43 to the frame and connected at the other end to the kick-ofi member 40 by means of the swinging link 44. Under normal circuit conditions thekick-off and toggle action parts are in the position shown in Fig. 4 Where the link 44 rests 2|. The parts are normally held in this position by the tension of the spring 35 through the medium of the actuator 24 which is pivoted to the kick-off member 49 as above described and when the toggle is in this position the switch may be operated to the on and ofi positions by means of the external handle 21 without effecting the toggle.

When, due to the passage of excessive current,

the bimetallic thermostatic strip l1 warps, it en- 'gages the outer end of the toggle arm 42 and forces that arm to swing about its pivot'43 sufficiently to break the toggle action and thus al-- position shown in Fig.

low the spring 35 to pull the actuator 24 inwardli and tilt the kick-ofi member 40 to the 6. A screw 45 is adjustably mounted in the outer end of the toggle arm 42 to serve as an abutment for the thermostatic strip. When the outer end of the thermostatic strip 11 forces the outer end of toggle arm 42 to the right as viewed in Fig. 4 the link 44 isv tilted outwardly. This tilts the kick-off arm 40 about its pivot 4| thus'swinging the pivot 25 of the lever 24 about the pivot 4|. A light spring '45 on the axis of the PM); .43 biases the arm 42 to the position shown in Fig. 4. The kick-off member 40 is provided with an extension finger 41 which coacts with the arm 23 of the switch memberl5 to aid in moving the switch member to the oil position when the switch is tripped by an overload. The lowering of the part 36 to which the spring 35 is attached, the movement oi the pivotal center 25 of the lever 24 and the action of the finger 41 tilts, the switch member l5 about its pivot 22 and reverses the action of the spring and causes it to snap the switchmember l5 to the open circuit position.

In case of a short circuit which may cause a dangerous surge it is desirable to open the circuit more quickly than is possible with an ordinary thermostatic device. For this reason I provide an overload magnetic device which includes the coil 19 previously mentioned and its pivoted armature 48. This armature has a pivoted flipper piece 49 which is adapted to coact with the toggle arm 42 to release it and open the circuit quickly upon occurrence of a severe overload or a short in the circuit. When there is an excessive surge in the circuit the magnet l9 will finger 41 engages the part 23 of the switch mem- I ber I5 and starts it toward the open circuit posi-' m tion to which position it is aided by the movement of .the pivot support 25 about the pivot 41 and by the action of the spring 35. The operative movement of the thermostatic strip l1 and the tip of the flipper piece 49 of the magnetic release are in the same general direction as that of the correlated portions of the toggle which construction greatly accelerates the switch-releasing movement of the toggle and thus increases the efliciency of the device.

When the mechanism has been tripped by an overload and the parts occupy the position shown in Fig. 6, it will be noted that the actuator member or handle part 24 stands in a position which is approximately midway between the positions which it occupies when actuated manually on" and oil. In order to re-set the switch it is merely necessary to swing the actuator 24 to the fully oiP position, the end 33 of .the horizontal arm of the actuator turning on the fulcrum 34 so that the kick-off member 40 will be tilted back to the position shown in Fig. 4 where the toggle arm 42 and link 44 will hold the parts in the normal operating position.

It will be seen from the foregoing that the mechanism is such that the switch cannot be held closed by hand against an overload because the tripping action throws the switch member to the "011? position even though the. handle may beheld in the on position.

It will be noted thatwhen the thermostatic element I1 is warped by the heat generated by the passage of an overload current it is moved in the same 'direction as the hinged switch member. The strip 11 moves the toggle device to the right and the attached'lever 40 clockwise about the pivot 4|. The arm 41 then engages the arm 23 and forces the switch member l5 to swing downwardly to open the circuit. The electro- *magnet operates to move the armature 43 and especially designed this switch so as to provide for both thermostatic and electromagnetic release, I contemplate that either one may be omitted and the other used and still utilize my invention as expressed incertain of the claims.

A number of the switches or circuit breakers may be mounted side by side as shown in Fig.

3 where the actuators 24* and 24" corresponding to the actuator 24 are connected for instance by cross pieces 53 so that a single finger piece 21' can be used to move a number of them at one time so as to open. and close all of the circuits. A somewhat similar connection for automatic action may be provided by providing the toggle arm 42' with an extension 55 and the toggle arm 42" with an extension 56. A tilting member 51 is pivoted in the casing and has forked arms engaged by the extensions 55 and 56 so that when any one of the toggle arms is tripped either by the heating of the thermostatic strip or by the action of the electromagnet trip the switch parts will be thrown to the open circuit position as previously described. An insulating partition 58 may be mounted between adjacent switch units.

As the toggle device supports the kick-off piece it is only necessary to connect the toggles loosely and join the members 24' and 24". When ganged in this manner the units maintain accuracy of calibration as each unit is entirely separate in its function.

It will be understood of course that such a circuit breaker may be enclosed in a manner similar to that shown in Fig. 1.

I claim:

1. In an electric circuit breaker, a pivoted switch member, a hinged kick-oil member, a toggle arm and link holding the kick-off member in its normal position, an actuator hinged to said kick-oil member, a throw-over spring connecting said actuator and said switch member, and overload responsive means for engaging the toggle arm and causing the kick-off member to move the actuator and switch member to open the circuit.

2. In an electric circuit breaker, a pivoted switch member, a hinged kick-off member for engaging the switch member, a toggle arm and link holding the kick-off member in its normal position, an actuator hinged to said kick-off member, a throw-over spring connecting said actuator and said switch member, and overload responsive means for forcibly moving the toggle arm and causing the kick-off member to move the switch member to open the circuit.

3. In an electric circuit breaker, a pivoted switch member, a hinged kick-off member, a toggle arm and link holding the kick-oil. member in its normal position, said kick-off member having an arm to engage the switch member, an actuator hinged to said kick-off member, a throwover spring connecting said actuator and said switch member, and overload responsive means for causing the kick-oil! member to move the actuator and switch member to open the circuit.

4.111 an electric circuit breaker, a pivoted switch member, a hinged kick-oil member, a toggle arm and link holding the kick-oil member in its normal position, an actuator hinged to said kick-off member, a throw-over spring connecting said actuator and said switch member overload responsive means for forcibly moving the toggle arm and causing the kick-off member to move the switch member to open the circuit and a fulcrum for said actuator to permit it .to be moved to reset the kick-off member and the toggle arm.

5. In an electric circuit breaker, a pivoted switch member, a hinged kick-off member, a toggle arm and link holding the kick-off member in its normal position, an actuator hinged to said kick-oil member, a throw-over spring connecting said actuator and said switch member, overload responsive means for causing the kick-oil member to move the actuator and switch' member to open the circuit and a fulcrum for saidactuator to permit it to be moved to reset the kick-off member and the toggle action.

6. In an electric circuit breaker, a pivoted switch member, a hinged kick-off member, a toggle arm and link constituting means for holding the kick-off member in its normal position, an actuator hinged to said kick-off member, a throw-over spring connecting said actuator and said switch member, overload responsive means for engaging the holding means and causing the kick-off member to move the actuator and switch member. to open the circuit and a fulcrum for said actuator to permit it to be moved to reset the kick-off member and the toggle action.

'7. A circuit breaker having a frame, a switch lever hinged to said frame, a member hinged to said frame and having an arm for engaging said switch lever to move it toward an open circuit position, an actuating member pivoted to said hinged member and having an extension adapted to fulcrum on the frame, a tension spring connecting said actuating member and said switch lever, a toggle arm and link releasable upon an overload for holding said hinged .member in its normal position under normal load conditions, said tension spring moving said actuating member, said hinged member and said switch lever to an open circuit position when said holding means is released upon an overload, said actuating member being tiltable about said fulcrum to reset the holding means.

8. In a snap switch, a hinged switch member;

a manually operable hinged actuator, an overcenter spring connecting the switch member and the actuator, a hinged kick-off member, a toggle device normally holding the kick-off member in position during manual operation of the actuator, means actuated by the kick-oil member for moving the switch member to open circuit position, and means responsive to an overload in the circuit for moving the toggle device and the kick-oil member in the same direction as the circuit opening movement of the switch member.

9. In a snap switch, a movable switch member, means for manually operating said switch member, means for moving the switch member to open the circuit upon an overload, said means including a kick-off lever, a thermostatic strip and a toggle device, said strip engaging said toggle device and forcibly moving the kick-01f lever and the switch member in the same general direction to open the circuit upon an overload.

10. In a switch, a movable switch member, a manually operable actuator for moving the switch member, a kick-oil member supporting said actuator and adapted to move the switch member to open circuit position, a toggle device normally holding the kick-off member in position, a thermostatiac device and an electromagnetic device each coacting with the toggle device to move it and the attached kick-oil device in the same general direction upon an overload in the circuit. 11. In a switch, a base plate, a frame supported by said plate, a switch member hinged in said frame, a kick-off member hinged in the frame at one side thereof and having an arm for engaging said switch member, an actuator hinged to said kick-off member, an overcenter spring connecting said actuator and said switch member, a toggle device hinged at one end to said frame and at the other end to said kick-off member, and a thermostatic strip connected to" one end of said base plate and coacting with the toggle device to move the kick-off member.

12. In a switch, a base plate, a frame supported by said plate, a switch member hinged in said frame, a kick-off member hinged in the frame at one side thereof and having an arm for engaging said switch member, an actuator hinged to said kick-off member, an overcenter spring connecting said actuator and said switch memher, a toggle device hinged at one end to said frame and at the other end to said kick-0K memher, a thermostatic strip connected to one end of said base plate and enacting with the toggle device to move the kick-off member and an electromagnetic device carried by the other end of said base plate and having an arm for engaging said toggle device to release the same.

RAYMOND N. ROWE. 

